In recent years, in the manufacturing of semiconductor devices, the Chemical Mechanical Polishing (CMP) method is in wide use for planarizing insulating films, metal films, polycrystalline silicon films or the like formed to fill in grooves formed on a substrate. The CMP method is a method which supplies a polishing agent (a slurry) containing abrasive grains and a chemical solution onto a polishing cloth and brings a work piece into contact with the polishing cloth, thereby planarizing a work surface by combining the chemical action of the chemical solution and the mechanical action of the abrasive grains. However, in the CMP method, mechanical damage caused by the abrasive grains may not be avoided, and there is a problem in that abrasion damage occurs on the work surface.
In relation to the problem, a method is being considered which avoids abrasion damage to the work surface by using a process liquid which does not contain the abrasive grains. For example, there is a method of planarizing a metal film surface by using the temperature rise of a portion in contact with the polishing cloth to chemically dissolve the heated portion with the process liquid. There is also a method of planarizing a silicon film, a silicon carbide film, a gallium nitride film, an aluminum oxide film, a metal film, or the like by bringing the work piece into contact with a solid plate formed from a catalyst and chemically dissolving a contacting portion using the process liquid.
However, there is no method proposed which planarizes a silicon oxide film essential for the manufacturing of semiconductor devices.